Frame grid holding apparatus



May 11, 1965 W. H- SIMMONDS FRAME GRID HOLDING APPARATUS Filed May 21', 1962 United States Patent 3,182,688 FRAME GRTD HQLDWG APPARATUS William H. Simmonds, Pulteney, N.Y., assignor to Westinghouse Electric fiorporation, East Pittsburgh, Pa, a corporation of Pennsylvania Filed May 21, 1962, Ser. No. 196,123 Claims. (til. 140-715) The present invention relates to apparatus for winding grid electrodes for use in electron tubes and, more particularly, to a guide adaptable to standard grid making machines for slidably retaining the frame strip of a frame type grid at a point near which the grid is being wound.

In the winding of conventional grids, that is, grids having only side rods and grid laterals wound thereon, the side rods are slid through holes or grooves in a mandrel which is held by the rotating lathe head or spindle. In the case of frame grids, however, this method will not work as the presence of the cross members between the side support rods prevents the frame strip from being held from the inside.

The prior art method of winding a strip of frame grids employed a technique whereby the grid strip was clamped at its extreme ends in a carriage, and the strip and its carriage were traversed past the winding point. Alternately, the winding point was made to traverse the length of a grid strip. By either technique, the strip was unsupported in its center portion when lateral wire was being Wound on this portion of the strip. Therefore, the strip length was largely limited by the mechanical strength of the grid strip in its ability to resist the bending force of the lateral wire tension rather than by machine or other considerations.

It is, therefore, an object of this invention to provide improved means for adapting a standard grid machine to the winding of frame type grids.

Another object is to provide an improved guide means for use in the winding of frame grids.

A further object is to provide an improved adjustable guide for the use with standard grid winding machines.

Briefly, the present invention provides a guide for slidably retaining a frame grid strip. This guide maybe mounted on the rotating spindle or head of a standard grid machine, or it may be maintained stationary. In either case, the grid strip is gripped at one end and drawn through the guide. The winding station or point is positioned closely adjacent this guide and thus the guide serves to support the strip against the bending occasioned by the winding of the grid laterals and to reduce this bending to a negligible amount. Thus, the total length of grid strip which may be utilized is limited largely by machine design and handling considerations.

Further objects and advantages of the invention will become apparent as the following description proceeds and features of novelty which characterize the invention will be pointed out in particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which:

FIG. 1 is a top plan view of the guide in accordance with the present invention;

FIG. 2 is a top plan view of the base member of FIG. 1;

FIG. 3 is a side elevational view, in section, of the base member taken along line III-III of FIG. 2;

FIG. 4 is a top plan view of the jaw member of FIG. 1;

FIG. 5 is a side elevational view of the jaw member of FIG. 1;

FIG. 6 is a side elevational view of a frame grid strip of the type which the guide of the present invention is designed to hold; and

FIG. 7 is an end view of the frame grid strip of FIG. 6.

3,182,538 Patented May 11, 1965 Referring now to FIGS. 1 to 5, there is shown a guide for holding a frame grid strip in accordance with the present invention. The guide comprises a base member 12 which is substantially cylindrical in shape and which is made of a suitable material such as steel. A suitable recessed portion 14 is provided in the base of the member 12 to permit the base to be fitted over the rotating head or spindle of a standard type grid lathe such as the disclosed in United States Patent No. 2,441,228, issued May 11, 1948. One or more internally threaded holes 16 (four are shown in the present example) are provided extending radially from the recessed portion 14 to the outside of the member 12. Each of the internally threaded holes 16 is provided with a threaded set screw 18 for securing the base member 12 to the rotating spindle of the grid lathe. The top surface of the member 12 is provided with a groove Zti which extends diametrically across the member 12.

In FIG. 6 there is shown a frame grid strip 30 of the type for which the present invention is designed. The end view of this strip 30 may be seen in FIG. 7. The strip 30 comprises a pair of support rods 31 which are held in a spaced relationship by a plurality of cross bars 32. The cross bars 32 are aflixed to the side rods 31 by a suitable means such as welding. The strip 30 is prefabricated prior to the winding of the grid in a manner well known in the art.

With reference once again to FIGS. 1 to 5, the base member 12 is provided with a centrally extending bore 22 which is concentrically positioned with respect to the cylindrical member 12. The bore 22 is of suflicient diameter to permit the longitudinal passage of the frame grid strip 30.

A pair of jaws 24 are positioned at the top of the base member 12 within the groove 26. The jaws 24 are preferably L-shaped and include a horizontal leg 26 and a vertical leg 28. The vertical legs 28 are preferably of sufficient length to encompass, at any one time, a plurality of the cross bars 32. Each of the horizontal legs 26 is provided with an elongated slot 34 extending therethrough. As shown in FIG. 1, the jaws 24 are positioned within the groove 2t? of the base member 12 in a manner to provide that the vertical legs 23 are adjacent one another. The jaws 24 are secured to the base member 12 by screws 36 which extend through the slots 34 into a pair of diametrically located, internally threaded holes 38 in the base member 12. It is thus readily apparent that the two jaws 24 are readily adjustable along a longitudinal line with respect to one another by loosening the screws 36 and sliding the jaws 24 within the groove 20. After the jaws 24 have been properly adjusted, the screws 36 are once again tightened to secure the jaws 24 in place.

Each of the vertical legs 28 is provided with a slot or groove 42 of substantially U-shaped configuration extending the length'thereof. Each groove 42 is provided, at its bottom, with an upstanding portion 44 extending the length thereof. This upstanding portion 44 is preferably slightly less in width than the diameter of the side rods 31 of the frame grid strip 31). By this arrangement, there is provided on either side of the portion 44 a recessed region 45 into which the ends of the cross bars 32 which extend beyond the side rods 31 may project so as not to bind upon the jaws 24 as the grid strip is drawn therethrough. The grooves42 are positioned so as to be opposed to one another when the jaws 24 are assembled onto the base member 12.

In the utilization of the present invention the base member 12 with the jaws Z4 is secured to the rotatable spindle of the grid lathe by means of the set screws 18. The grid strip 36 is then inserted through a bore within the spindle, through the bore 22 of the member 12 and positioned between the legs 28 and within the grooves 42.

The jaws 2d are now adjusted so that they are symmetrically located with respect to the bore 22 and so that the up-raised portion 44 of the grooves 42 preferably have about .001 inch clearance with respect to side rods 31 of the grid strip 3 9. The side walls of the groove :2 are preferably spaced to provide a clearance of about .002 inch between the cross bars 32 and the side Walls of the groove 42. In this manner, the grid strip 35) is retained in position and yet is free to slide within the legs 28.

In the grid winding operation, one end of the grid strip 30 is secured to suitable means, such as a draw bar, which provides to the strip 39 both rotary motion about and linear motion along its longitudinal axis. The lathe spindle, and hence the guide of the present invention which is secured to the spindle is rotated at a speed synchronous with that of the draw bar. A suitable means for directing the grid laterals onto the grid strip 36! is positioned at a point near to the free ends of the vertical legs 23.

Thus, as the grid laterals are drawn onto the rotating strip 30, the guide of the present invention provides the requisite support to prevent the bending of the strip 3h.

Thus, it is seen that there has been provided a guide which will accurately, but slidably retain a frame grid structure. It is apparent that if a grid strip 36* having a different spacing between the side rods 31 is used, it is only necessary, with the present invention, to adjust the jaws 2d longitudinally with respect to one another. Likewise, while the example shown is one having a fixed distance between the side Walls of the groove 42, it is evident that a universal type jaw utilizing shims may be utilized for accommodating a plurality of grid strips of different thickness. However, with the fixed spacing between the side walls of the groove 42, if a change to a grid size of different thickness is desired, it is only necessary to replace the two jaw members 24 by similar jaw members having different groove spacings. This change is readily and easily acomplished.

Although the invention has thus far been explained as being mounted on the rotary spindle of a lathe or other suitable grid Winding machine, it has equal application as a stationary member through Which a grid strip 3%; is drawn. In this latter embodiment the strip 3% is provided with only linear motion and the grid laterals are placed on the strip 30 through the utilization of a suitable winding head which rotates around the strip 3b. Here, as before, the winding should take place at a point which is in close proximity to the free end of the legs 28.

While there have been shown and described what are at present considered to be the preferred embodiments of the invention, modifications thereto will readily occur to those skilled in the art. It is not desired, therefore, that the invention be limited to the specific arrangement shown and described and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

I claim as my invention:

1. In a grid winding machine, a guide for slidably retaining a grid frame having spaced side rods and cross members extending between said side rods comprising a 'base member, a groove within said base members, and a pair of jaw members supported within said groove and adjustable with respect to one another along the length of said groove, each of said jaw members having a surface extending substantially prependicular to the surface of said base member, a groove in each of said jaw surfaces, said latter grooves being of substantially U-shaped configuration and having an upstanding portion in the base til 10 opening to permit longitudinal passage of said grid frame,

first and second jaw members securable to said base member, and a first and second surface means within said jaw members for slidably retaining said grid frame within said jaw members, said first surface slidably contacting U only one of said side rods and second surface slidably contacting only said cross members.

3. In a grid winding machine, a guide means for slidably retaining a grid frame having spaced side rods and cross members extending between said side rods comprising a base member, a pair of spaced jaw members adjustably mounted on said base member and secured thereto, a groove within one surface of each of said jaw members for retaining said grid frame, said groove member comprising an upstanding portion at the base of said groove slidably contacting only the side rods of said grid frame and the side Walls of said grooves slidably contacting only said cross members of said grid frame.

4. In a grid winding machine, a guide for slidably retaining a grid frame, said grid frame having spaced side rods and cross members extending between said side rods, said guide comprising a base member, first and second substantially L-shaped jaw members secured to said base member in opposed relationship with each other, one leg of each of said jaw members being in contact with said base member, the other leg of each of said jaw members being provided with a groove in one surface and an upstanding portion at the base of said groove for slidably retaining said grid frame within the grooves of said jaw members, said side rods in slidable contact with said upstanding portion and said cross members being in siidable contact with the side walls of said groove,

5. In a grid winding machine, a guide for slidably retaining a grid frame having spaced support rods and cross members extending between said side rod comprising a base member, a groove within the surface of said base member, first and second L-shaped jaw members each having a first and second leg, said first leg adjustably retained within said groove and securable to said base member, said second leg of each of said jaw members extending in a direction substantially perpendicular to the surface of said base member, said second legs having a first and second surface longitudinally extending in opposed faces for slidably retaining said grid frame Within said jaw members, said first surface substantially perpendicular to the surface of said base for slidably contacting only said side rods, said second surface substantially perpendicular to said first surface and the surface of said base for slidably contacting only said cross members.

References Qited by the Examiner UNITED STATES PATENTS 2,523,374 9/50 Jensen 279-123 2,708,118 5/55 Kuchenbrod 279123 CHARLES w. LANHAM, Primriry Examiner. WILLIAM F. PURDY, Examiner. 

1. IN A GRID WINDING MACHINE, A GUIDE FOR SLIDABLY RETAINING A GRID FRAME HAVING SPACED SIDE RODS AND CROSS MEMBERS EXTENDING BETWEEN SAID SIDE RODS COMPRISING A BASE MEMBER, A GROOVE WITHIN SAID BSE MEMBERS, AND A PAIR OF JAW MEMBERS SUPPORTED WITHIN SAID GROOVE AND ADJUSTABLE WITH RESPECT TO ONE ANOTHER ALONG THE LENGTH OF SAID GROOVE, EACH OF SAID JAW MEMBERS HAVING A SURFACE EXTENDING SUBSTANTIALLY PREPENDICULAR TO THE SURFACE OF SAID BASE MEMBER, A GROOVE IN EACH OF SAID JAW SURFACES, SAID LATTER GROOVES BEING OF SUBSTANTIALLY U-SHAPED 